Research on suction equilibrium time of unsaturated reticulate red clay

The suction,yield and strength characteristics of unsaturated intact loess based on true tri-axial tests

“…Filter paper technique, humidity control technique, and axis translation technique were used to study suction equilibrium time of unsaturated reticulate red clay. Test results show that suction equilibrium exists in both suction measurement or suction control using any technique in the tests, and the suction equilibrium time in measuring matric suction of unsaturated reticulate red clay with axis translation technique is shorter than that using filter paper technique (Li et al, 2018). Compression and shear behaviors of intact loess and loosely compacted loess were investigated via unsaturated direct shear tests; despite significant volumetric strain upon wetting (up to 14%), suction-induced volumetric shrinkage is less than 2% for all suction levels considered because of the as-compacted moisture content at the dry side of the optimum value.…”

“…Therefore, the influence of suction must be focused on the research about the engineering properties of unsaturated soils. Aiming at the problem of strength and deformation of unsaturated soil, many scholars (Zhan et al,2006;Liao et al, 2005;Zhang et al, 2009;Chen, 1999;Li et al, 2014;Li et al, 2018;Ng et al, 2016;Xing et al, 2016;Lin et al, 2007;Hu et al, 2005) have carried out a large number of experiments under different stress paths for remolded disturbed or undisturbed unsaturated soils by using unsaturated direct shear apparatus and unsaturated triaxial apparatus, and many valuable results have been achieved. A series of tests, such as moisture absorption tests, equal suction-compression-consolidation tests, and shear tests, on unsaturated expansive soil using unsaturated soil triaxial apparatus with control suction were performed.…”

“…For most researches on unsaturated loess, experiments have been conducted under the condition of controlling suction with the remolded soil selected as the research object (Zhan et al, 2006;Zhang et al, 2009;Chen et al, 1999;Li et al, 2014;Li et al, 2018;Ng et al, 2016;Lin et al,2007). In recent years, under the condition of measuring suction, the isotropic compression and triaxial shear tests on intact loess of different initial suction by using unsaturated soil triaxial apparatus were performed, and a lot of valuable conclusions were obtained with many factors being studied, such as the deformation characteristics, critical state, yield, and suction variation characteristics of unsaturated intact loess under constant water content.…”

Experimental Study on Viscoplastic Property of Unsaturated Reticulate Red Clay Used as an Engineered Barrier

“…The peripheral pressure, axial pressure, pore air pressure, and pore water pressure could be controlled independently and arbitrarily. The air pressure and water pressure of the specimens were controlled using the perforated plate in the specimen cap and the ceramic plate in the specimen bottom, respectively [67,68]. The test range and accuracy of GDS unsaturated triaxial apparatus are 1.0 MPa and 0.1 kPa, respectively.…”

Optimization of Ionic Soil Stabilizer Dilution and Understanding the Mechanism in Red Clay Treatment

“…Since the red clay has swell-shrink characteristics and high plasticity index [1][2][3], it often induces many geo-hazards such as road cracking, uneven foundation settlement, slope instability, pit deformation, and destruction [4][5][6]. It was realized that the traditional soil solidifying materials such as cement, lime, and flyash had drawbacks of high costs and long construction periods, which could not meet the needs of the construction and social development [7,8]. In order to increase the strength and reduce the deformation of the red clay, the Ionic Soil Stabilizer (ISS) was considered as an alternative.…”